In a wireless network, in the case where a source node and a destination node are connected by a one-hop direct link, cooperative communication (Cooperative Communication, CC) is usually adopted to improve the reliability of communication. As a communication manner, cooperative communication may enable a single-antenna mobile station to obtain a gain which is similar to that in a multiple input multiple output (Multiple-Input Multiple-Output, MIMO) system.
A basic idea of cooperative communication is as follows: In a multi-user environment, single-antenna mobile stations may share their antennas according to a certain manner to generate a virtual MIMO system and obtain a transmit diversity gain. Cooperative communication makes use of an antenna of another idle node in the wireless network. When the source node sends information to the destination node, the information is also sent to the idle node at the same time, and then the idle node forwards the information to the destination node. Thus, a node utilizes not only its own spatial channel but also a spatial channel of the idle node, so that a cooperative diversity is generated for the communication, and a virtual MIMO system is generated, which may effectively increase system capacity, enhance network quality, and improves system performance. Cooperative communication methods include a decode-and-forward mode, an amplify-and-forward mode, and a coding-and-forward mode.
In the decode-and-forward (Decode-and-Forward, DF) mode, a cooperative node first attempts to detect data bits of the source node, and then resends the detected bits.
In the amplify-and-forward (Amplify-and-Forward, AF) mode, a cooperative node receives a signal with noise, where the signal with noise is sent by the source node, then amplifies the signal, and resends the amplified signal with noise. A base station makes a combined decision on data transferred by a user and its partner.
The coding-and-forward (Coding-and-Forward, CF) mode is a combination of a channel coding idea and cooperation. In the coding-and-forward mode, two independent fading channels are used to send different parts of each user codeword. A basic idea is that every user sends additional redundant information to its partner. When a channel between them is very bad, this mechanism is automatically restored to a non-cooperation mode. An outstanding characteristic of this mechanism is that cooperation is implemented through channel coding design without the need of feedback between users.
In practical applications, for a decentralized control network, cooperative communication adopts a distributed cooperation protocol, where a user node may independently decide at any time which user to cooperate with, and every user node has at least one partner to provide a second path, so as to form a diversity.
During the process of implementing the present invention, the inventor discovers that the prior art has at least the following disadvantage: The cooperative communication adopting the distributed cooperation protocol is only applicable to the case where there is only a one-hop direct link between the source node and the destination node, and for the case where there is multi-path multi-hop routing between the source node and the destination node, no corresponding cooperative communication method is available to improve performance of a communication process.